War driving is the process of traveling around looking for wireless access point signals that can be used to get network access.
War Driving (Wikipedia)
Wardriving is the act of searching for Wi-Fi wireless networks, usually from a moving vehicle, using a laptop or smartphone. Software for wardriving is freely available on the internet.
Warbiking, warcycling, warwalking and similar use the same approach but with other modes of transportation.
